Steve,
the only one I am aware of is the Aerosport one,
I cant find anything with this name, is it spelt differently ?, do you have any links ?
I'll wager you won't be able to help yourself with regards to tear-arsing, that is pretty much their sole purpose.
The reason I chose it over the Sport is the riding position. I find that I tend to be much calmer if I'm upright, with clip-ons I just ride like an arse everywhere, thats why I sold the SZR, I liked the motor but I couldnt just potter along on it.